Plastic and fibreglass flange for surge tanks

ABSTRACT

The present patent relates to the sector of surge tanks for pumps and boilers, and particularly concerns a new flange made of plastic and fibreglass for assembling on surge tanks The flange has a dome-like geometrical shape, that is concave on the underside, designed to reinforce it and to reduce the amount of material needed to make it. Said flange is distinctive in that it is shaped so as to ensure perfect geometrical compatibility with the surge tank on which it is assembled and the tightness of the butyl (or other material) seal.

The present patent relates to the sector of surge tanks for pumps andboilers, and particularly concerns a new flange made of afibreglass-reinforced plastic material for assembling on such surgetanks

In the sector of surge tanks for pumps and boilers, there are currentlyvarious known types of flange for assembling on surge tanks A known typeof flange comprises a stainless steel plate with a welded threadedconnection on the plate and 6 holes homogeneously distributed around itscircumference. Said flange is suitable for being assembled on the bodyof a surge tank, on a flat threaded ring, by tightening it in place with6 corresponding screws. The edge of the butyl (or other elastomer)membrane in the surge tank is inserted between the flange and the ringto serve as a seal.

Another type of known flange consists of a galvanised steel platecomplete, as in the previous case, with a threaded connection weldedonto the plate and 6 holes evenly distributed around its circumference.Said flange is designed to be assembled on the body of the surge tank ona flat threaded ring, by tightening it in place with 6 correspondingscrews. The edge of the butyl (or other elastomer) membrane in the surgetank is inserted between the flange and the ring to serve as a seal.

The above-described types of flange for assembling on surge tanks haveseveral drawbacks. While the first type, being made of stainless steel,affords a high level of resistance to the effects of corrosion oroxidation in contact with the water on the one hand, on the other itentails particularly high production costs.

The second, being made of galvanised steel, is more vulnerable to theaggressive action of the water and has production costs that, thoughlower than in the former case, are still high.

To overcome the above-mentioned drawbacks, a new type of thermoformedflange has been designed, preferably made of polypropylene andfibreglass, for assembling on surge tanks The main technical aim of thenew type of flange is to eliminate the above-mentioned drawbacks of theknown state of the art.

As part of the main goal, an important object of the present inventionis to reduce the production costs, without affecting the quality leveland efficacy of the flange. Another important object of the presentinvention is to eliminate the corrosive-oxidising effects due to theaction of the water.

Another important object of the present invention is to ensurecompliance with non-toxic requirements for use with foodstuffs.

Another important object of the present invention is to be completelysuitable for recycling.

These and other direct and complementary objects are achieved by the newinvention, a thermoformed flange for assembling on surge tanks, made ofpolypropylene and fibreglass. The characteristics of the new inventionare better clarified by the description that follows, with reference tothe drawings, which are attached as a non-limiting example.

The attached drawing gives a non-limiting example of a practicalembodiment of the invention.

FIG. 1 shows a cross-sectional view of the flange;

FIG. 2 shows a view from above;

FIG. 3 shows a view from above of the flange in a possible embodimentwith four holes (F1-F4).

With reference to the figures previously mentioned and presented in theattached drawing 1, the flange (A) is circular in shape and completewith 4 or 6 holes, (F1-F4 or F1-F6), evenly distributed around itscircumference and suitable for containing screws for fixing the flangeto the surge tank.

Coinciding with said holes, there are suitable seats (S1-S4 or S1-S6)designed to provide ample space for the insertion of fixing tools. Theflange (A) comprises a threaded connection (B) located at its centre anddesigned for its connection to the hydraulic system. As shown in thecross-sectional view in FIG. 1, the flange has the geometrical shape ofa dome (A1), the lower portion (A2) being concave, designed to make theflange stronger and to reduce the quantity of material required.

The flange can also be thermoformed in another geometrical shapecomprising a cylindrical disc-shaped body with suitable holes for thefixing screws, and with cross walls in the upper portion, again for thepurpose of reducing the quantity of material required and increasing itsstrength. The geometries obtained ensure a perfect geometricalcompatibility with the surge tank on which the flange is assembled andthe tightness of the seal assured by the butyl (or other elastomer)surge tank lining. Moreover, this shaping is straightforward andsuitable for enabling the flange to be manufactured by injectionmoulding, with a consequently marked reduction in production costs.

The new thermoformed flange is preferably made of a polypropylene(Tecnoprene) and fibreglass.

From studies conducted, this plastic material was found the mostsuitable for various reasons:

it is certified as non-toxic by the Food and Drug Administration andconsequently suitable for applications with foodstuffs;

it is unaffected by the corrosive-oxidising effect of water;

it is fully recyclable.

From the tests conducted, the flange was found amply compatible with thetemperatures and pressures to which it is submitted even in extremeworking conditions.

In practice, it was established that the present invention provides asolution to the previously-stated technical goal and objects.

Thus, with reference to the above description and to the attacheddrawing, the following claims are advanced.

1. A flange for assembling on surge tanks in water, heating and sanitarysystems, characterised in that it is made of a thermoformed materialconsisting of polypropylene and fibreglass.
 2. A flange according toclaim 1, characterised in that it comprises a circular crown on itsunderside, with suitable holes for containing fixing screws.
 3. A flangeaccording to claims 1 and 2, characterised in that it can comprise anupper portion with a dome-shaped upper surface and a concave lowersurface.
 4. A flange according to claims 1, 2, characterised in that itcan comprise an upper portion with a circular body with upperreinforcement cross walls.
 5. A flange according to claims 1, 2, 3 and4, characterised in that, in the upper portion, it comprises a threadedconnection thermoformed therewith, suitable for ensuring the flange'sconnection to the hydraulic system.
 6. A flange according to claims 1,2, 3, 4 and 5, characterised in that said material consists of thepolypropylene Tecnoprene.
 7. A flange according to claims 1, 2, 3, 4, 5and 6, characterised in that said thermoformed material containsfibreglass.
 8. A flange according to claims 1, 2, 3, 4 and 5,characterised in that it comprises fixing holes and seats that are widerthan the holes for the corresponding screws, in order to providesufficient space for the fixing tools.
 9. A flange according to any orany combination of the previous claims, characterised in that itcomprises all the above-described characteristics, as shown and claimedin the present patent.